Tuesday, April 30, 2019

“Orders” must come before “Invoicing” in Presto main menu

Wow, I had a subtle problem (#2977) : The ledger plugin was being installed automatically by vat (which in turn was installed automatically by invoicing). So when building the main menu, Lino assumed that ledger came after invoicing. But invoicing adds a command to the Sales menu (and therefore creates the top-level menu) while the Orders main menu is created only later by ledger. It took me some time to find the explanation of this irritating behaviour. I fixed it by explicitly installing ledger.

But how to avoid this pitfall for other application developers? Actually the ledger plugin does not need to get installed explicitly because it is automatically installed by invoicing and vat.

The lino_xl.lib.ledger plugin has a complex setup_main_menu method which should run before that of the invoicing plugin.

Actually the lino_xl.lib.invoicing plugin behaves wrongly. It assumes in a hard-coded way that we have a “Sales” journal group and menu item, and then adds its “Create invoices” action there. This is an even more complex problem: #2978 (How to integrate “Create invoices” action into the main menu). In Lino Tera they will probably want to have two actions for generating invoices in their main menu because they have two therapy centers in two different towns. They have three sales journals: one for the first town, one for the other town, and a third one for manually created invoices.

I checked in my recent changes for Lino Presto, with some application changes and the menu sorting now finally fixed.

I undid my change “Choicelists are now always sorted by their value”, originally just a quick note in lino.changes.2019, but as it turns out now the topic is more complex and deserves its own #2975. Choicelists a re in natural order by default. For example we definitively don’t want to sort lino_xl.lib.cal.DurationUnits or lino_xl.lib.cal.Recurrencies.

There are choicelists we want to sort. We must do this explicitly by calling the new sort method. The post_site_startup method is a good place for sorting your choicelist. For example lino.modlib.checkdata sorts its Checkers, lino.modlib.printing sorts its BuildMethods and lino_xl.lib.ledger sorts its CommonAccounts like this.

Note that on_site_startup is too early for sorting the choicelists, at least for lino_xl.lib.ledger because you can have lazy voucher type definitions which get added only afterwards.

Note that lino_xl.lib.orders sorts lino_xl.lib.ledger.JournalGroups, i.e. a choicelist defined in another plugin. That’s also possible.

Note the sorting order of lino_xl.lib.cal.EntryStates in cal : Calendar plugin for Lino Welfare: the published state has been added later (by the feedback module) and is not at the “logical” place. Until now nobody complained that it is a the end of the choice list. But this is an example of a choicelist which should get sorted. All workflows should be sorted by their value. The ordering of the entry states influences how the resulting workflow actions are displayed in workflow_buttons field of a calendar event.

I repaired some test cases in book and welfare. One was caused by a change of a help text, some others helped me to better understand when we want to sort choicelists.